In Part 4.1, we take a step back and look at where Genome Toolkit is going next. We introduce refactoring, explain why our small project is ready to grow into a proper scientific Python package, and show how this gives us a cleaner foundation for future biological tools and experiments. We also look at something pretty exciting: by building Genome Toolkit properly now, we are gradually making it AI-ready for future APIs, MCP tools, and AI agents.